U.N. Officials Warn of an Accelerating Humanitarian Crisis

BEIT LAHIYA, Gaza Strip—A barrage of shells struck a United Nations-run shelter on Thursday in a densely populated area that residents said had been under Israeli assault for days, killing at least 16 people, according to the Palestinian Health Ministry.

Israeli officials said they didn't yet know what hit the shelter in the northern Gaza town of Beit Hanoun, but acknowledged there were Israeli firefights with Hamas, the Islamist...